Two relay control circuit for automotive vehicles

ABSTRACT

A circuit for enabling the accessories, starter solenoid, ignition circuit and gauges of an automotive vehicle includes an ignition switch with its movable contact connected to ground through a key and two output conductors, each in series with a relay, which are selectively energized, singly or together, according to the switch position. A switching network containing several switches, each operated by one of the relays, is arranged so that the low power accessories are energized when the switch is in the off position and one relay is energized, the starter solenoid ignition circuit and the gauges are energized when the switch is in the start position and both relays are energized, and all the utilization circuits are enabled when the switch is in the on position and the second relay is energized. An auxiliary circuit provides for horn operation and audible warnings when the vehicle lights are on or the key is inserted in the ignition switch when a vehicle door is open.

United States Patent 1 Ballou July 10, 1973 TWO RELAY CONTROL CIRCUITFOR AUTOMOTIVE VEHICLES [75] Inventor: Richard P. Ballou, Howell, Mich.

[73] Assignee: General Motors Corporation,

Detroit, Mich.

22 Filed: May 22, 1972 21 Appl. No.: 255,790

Primary Examiner-Robert K. Schaefer Assistant Examiner-William J. SmithAtt0rney -Warren D. Hill [57] ABSTRACT A circuit for enabling theaccessories, starter solenoid, ignition circuit and gauges of anautomotive vehicle includes an ignition switch with its movable contactconnected to ground through a key and two output conductors, each inseries with a relay, which are selectively energized, singly ortogether, according to the switch position. A switching networkcontaining several switches, each operated by one of the relays, isarranged so that the low power accessories are energized when the switchis in the off position and one relay is energized, the starter solenoidignition circuit and the gauges are energized when the switch is in thestart position and both relays are energized, and all the utiliza' tioncircuits are enabled when the switch is in the on position and thesecond relay is energized. An auxiliary circuit provides for hornoperation and audible warnings when the vehicle lights are on or the keyis inserted in the ignition switch when a vehicle door is open.

3 Claims, 1 Drawing Figure PARKING LIGHT CIRCUIT 'H'GH P'Wvl R LON POWERSTARTER 1!,Nl l ION GAUrES lACC! *JLOHP; ACCESSORIES SOLENOII (mam rPatented July 10, 1973 PARKING LIGHT CIRCUIT GAUGES IGNITION CIRCUITSTARTER SOLENOID HIGH POWER LOWPOWER ACCESSORIES ACCESSORIES TWO RELAYCONTROL CIRCUIT FOR AUTOMOTIVE VEHICLES This invention relates to acontrol circuit for automotive vehicle electrical equipment.

A large number of vehicle electrical devices are controlled according tothe position of the ignition switch, e.g., high power accessories, lowpower accessories, starter solenoid, ignition circuit and gauges.Traditionally, to effect the required controls, a large number ofconductors are routed through the vehicle steering column to anelaborate ignition switch. According to the present invention, only twowires extending through the steering column to a very simple ignitionswitch are required. To accomplish other functions normally controlledat the steering column, it is necessary to add only two wires for signalcircuits and one wire for a horn.

It is therefore an object of this invention to provide an electricalcircuit control for an automotive vehicle which minimizes the number ofwires extending to the ignition switch.

It is another'object of the invention to provide an electrical circuitcontrol for an automotive vehicle having two conductors selectivelyenergized by the ignition switch, each controlling a relay forselectively enabling vehicle utilization devices in response to theenergization of either or both of the relays.

The invention is carried out by providing two relays, each connected toa switch by a single conductor for selective energization thereof and aswitching network including several contacts of the relays forselectively supplying power to high power accessories, low poweraccessories, the starter solenoid, the ignition circuit or gaugesaccording to whether one or the other of the relays, or both, isenergized.

The above and other advantages will be made more apparent from thefollowing specification taken in conjunction with the FIGURE which is aschematic electrical diagram of an automotive vehicle electrical circuitcontrol according to the invention.

A key-operated ignition switch includes a movable contact 12 which ismoved according to the rotation of a key 14. The contact 12 is connectedthrough a contact element 16 and the key 14 to ground so that the switch10 is connected to ground only when the key 14 is inserted in theignition switch to make a circuit with the contact 16. The stationarycontacts of the switch 10 include a contact 10a in ignition lockposition, contact 10b in off position and contact 100 in start position,which contacts are all electrically connected to a first conductor 18extending through the steering column 20 represented by broken lines. Afurther stationary contact 10d bridges the on and start positions of theignition switch and is connected to a second conductor 22 extendingthrough the steering column.

Other wires in the steering column include the horn control line 24which is connected to ground through a horn button 26 and a pair ofwires 28 for controlling signal circuits and connected to turn signalswitch 30 and a hazard warning switch 32. The details of the signalcircuits are set forth in the U.S. Pat. application of Richard P.Ballou, Ser. No. 162,234, filed July 13, 1971.

The first conductor 18 is connected to the coil of a relay 34, while thesecond conductor 22 is connected to the coil of a relay 36. The relayscontrol a switching circuit which selectively connects the vehiclebattery or power supply 38 to utilization devices on the vehicle whichinclude high power accessories 40, low power accessories 42, the startersolenoid 44, an ignition circuit 46, and gauges 48. Contacts in theswitching circuit controlled by relays 34 include normally closedcontacts 34a, 34b and 34c as well as normally open contacts 34d, 34e and34f. Similarly, the relay 36 includes normally open contacts 36a and 36band normally closed contacts 360. The coil of the relay 34 is connecteddirectly to the battery 38 so that when the line 18 is grounded throughthe switch 10, the relay 34 is energized. The coil of relay 36 isconnected to 'the battery through normally closed contacts 340 so thatwhen the line 22 is grounded through the switch 10, the relay 36 isenergized, provided the contacts 340 have not been opened due to a priorenergization of relay 34. When, however, the relay 36 does becomeenergized, the contacts 36a are closed to supply an alternate conductingpath to relay 36 through a diode 50 so that the relay 36 is latched inan energized state so long as line 22 is grounded; the subsequentenergization of relay 34 does not interrupt the current thereto. Thisarrangement requiring the relays 36 to be energized prior to the relay34, provides a safety feature since, as will be described below, bothrelays must be energized to enable the starter solenoid 44. Thus thechances of accidentially starting the vehicle due to shorting of thelines 18 and 22 is minimized since the wires would both have to beshorted in proper sequence to energize the starter.

The contacts 34a and 36c are connected in parallel between the battery38 and a junction point 52. That junction point is connected throughcontacts 36b to the high power accessories 40. Contacts 34d when closed,connect the junction point 52 to the low power accessories 42. Thecontacts 36:: are connected between the battery 38 and a junction point54. Junction point 54 is connected through contacts 34b to the low poweraccessories 42. The junction 54 is also connected directly to the gauges48 and is connected to the ignition circuit 46 through an ignition coildropping resistor 56. Contacts 34f are arranged in parallel with theresistor 56 to provide a resistor bypass during starting. The startersolenoid 44 is connected to junction point 54 through contacts 34c and aneutral safety switch 58 which is preferably mechanically connected tothe transmission range selector or gear shift of the vehicle so theswitch 58 is closed only when the transmission is in a neutralcondition.

In operation of the circuit thus far described, when the key 14 isinserted into the ignition switch and the switch is in either the keylock or off position, the relay 34 will be energized to open contacts34c and close contacts 34d so that power will be supplied to the lowpower accessories 42 through contacts 36:. and 34d and no other portionof the circuit will be energized. When the switch 10 is moved throughthe on position to start position, the relay 36 will first be energizedand then relay 34 will be energized to switch all the contacts to acondition opposite that shown in the drawing. Thus contacts 34a, 34b and36c will be .open to prevent any power or any current flow to theaccessories. Contacts 36a, 34a and 34f will be closed to supply power tothe gauges, to the ignition circuit through the bypass contact 34f andto the starter solenoid, provided that the neutral safety switch 58 isclosed. Then, when the engine is started and the ignition switch isreturned to on position, the relay 34 will be deenergized to open thebypass contacts 34f and close the contacts 34a and 34b so that currentwill be supplied to both sets of accessories.

Optionally, certain accessories may be connected at junction points 52and 54 if operation thereof is desired when these points are energized.

The circuit for operating the horn and the audible signal for indicatinglights on or that the key is in place in the ignition switch when thedrivers door is open, has power supplied from the low power accessorycircuit via line 60 to the emitter of the transistor 62 which has itsbase connected through a resistor 64 and a diode 66 to the line 18 sothat the transistor will be in an on state when the switch is in lock oroff position. A bias resistor 68 is connected between the emitter andbase of the transistor. The collector is connected through the coil 70of the horn buzzer relay 72 to normally closed contacts 74 of the relay,which in turn are grounded when a key door switch 76 is closed, as whenthe driver's vehicle door is open. The normally open contacts 78 of thehorn relay are connected between the input line 60 and the horn 80. Thelow voltage side of the relay coil 70 is connected through a diode 82 tothe horn button 26. In addition, the base resistor 64 is connectedthrough a diode 84 to the horn button 26. The vehicle parking lightcircuit is connected to the high voltage side of the relay 70 throughnormally closed contacts 36d operated by the relay 36 and a diode 86.

In operation of the warning circuit, closing the horn button 26 groundsthe base of the transistor 62 through the diode 84 to render thetransistor conductive if the line 60 is energized as when the key is inthe lock, off or'on position, and grounds the relay coil 70 throughdiode 82 so that the relay is energized to close the contacts 78 andenergize the horn 80. Thus, the horn may not be energized when the key14 is removed from the switch. When the door switch 76 is closed and thevehicle lights are on, the relay coil 70 is energized through thecontacts 36d, diode 86 contacts 74 and switch 76 to cause the contacts74 to intermittently open and close to produce a buzzing sound therebywarning the vehicle operator that the lights are on when the door isopen. Of course, the buzzer will not operate when the contacts 36d areopen as when the ignition switch is in the on position. Similarly, thecontacts 74 are caused to buzz when the key 14 is in the switch, therebyrendering transistor 62 conductive and the door switch 76 is closed tocomplete a circuit through the transistor, the coil 70, the contacts 74and the door switch 76. This, of course, provides a warning that thekey14 has been left in the switch when the door is open.

It will thus be seen that this invention minimizes the wiring requiredin the steering column by using only two wires for energizing two relaysfor selectively enabling the high power accessories, the low poweraccessories, the starter solenoid, the ignition circuit and the gauges.

The embodiment of the invention described herein is for purposes ofillustration and the scope of the invention is intended to be limitedonly by the following claims.

It is claimed:

1. A circuit for an automotive vehicle for operating an ignitioncircuit, a starter solenoid and accessories, including apower supply andcomprising first and second conductors,

first and second relays connected to the first and second conductorsrespectively,

a switch means connected for selectively completing circuits with theconductors and the power supply for energizing the relays singly and incombination,

and a switching circuit from the power supply to the ignition circuit,the starter solenoid and the accessories comprising contact meansactuated by the first relay for supplying power to the accessories whenthe first relay alone is energized, and

other contact means actuated by the first relay and contact meansactuated by the second relay for supplying power to the starter solenoidand the ignition circuit when both relays are energized,

the contact means actuated by the second relay supplying power to theignition circuit and the accessories when the second relay only isenergized.

2. A circuit for an automotive vehicle for operating an ignitioncircuit, a starter solenoid and two groups of accessories, including apower supply and comprising first and second conductors,

first and second relays connected with one side of the power supply andconnected to the first and second conductors respectively,

a switch connected for selectively completing circuits with theconductors and the other side of the power supply for energizing therelays singly and in combination,

and a switching circuit from the power supply to the ignition circuit,the starter solenoid and the accessories comprising contacts actuated bythe first relay for supplying power to one group of accessories when thefirst relay alone is energized,

other contacts actuated by the first relay and con-' tacts actuated bythe second relay for supplying power to the starter solenoid and theignition circuit when both relays are energized, and means including thecontacts actuated by the second relay and normally closed contacts ofthe first relay for supplying power to the ignition cir cuit and bothgroups of accessories when the second relay only is energized. 3.A-circuit for an'automotive vehicle for operating an ignition circuit, astarter solenoid, and first and second groups of accessories, includinga power supply and comprising first and seocnd conductors,

first and second relays connected with one side of the power supply andconnected to the first and second conductors respectively,

a key operated ignition switch connected for selectively completingcircuits with the conductors and the other side of the power supply forenergizing the first relay when in a first switch position, the secondrelay when in a second switch position, and both relays when in a thirdswitch position, the key forming a part of the switch and being inseries with the power supply so that the circuits can be energized onlywhen the key is inserted in the key operated switch,

and a switching circuit from the power supply to the ignition circuit,the starter solenoid and the accessories comprising are energized, andmeans operative when the second relay only is energized including thecontacts closed by the second relay for supplying power to the ignitioncircuit, and normally closed contacts of the first relay and furthernormally open contacts closed by the second relay for supplying power toboth groups of accessories.

1. A circuit for an automotive vehicle for operating an ignitioNcircuit, a starter solenoid and accessories, including a power supplyand comprising first and second conductors, first and second relaysconnected to the first and second conductors respectively, a switchmeans connected for selectively completing circuits with the conductorsand the power supply for energizing the relays singly and incombination, and a switching circuit from the power supply to theignition circuit, the starter solenoid and the accessories comprisingcontact means actuated by the first relay for supplying power to theaccessories when the first relay alone is energized, and other contactmeans actuated by the first relay and contact means actuated by thesecond relay for supplying power to the starter solenoid and theignition circuit when both relays are energized, the contact meansactuated by the second relay supplying power to the ignition circuit andthe accessories when the second relay only is energized.
 2. A circuitfor an automotive vehicle for operating an ignition circuit, a startersolenoid and two groups of accessories, including a power supply andcomprising first and second conductors, first and second relaysconnected with one side of the power supply and connected to the firstand second conductors respectively, a switch connected for selectivelycompleting circuits with the conductors and the other side of the powersupply for energizing the relays singly and in combination, and aswitching circuit from the power supply to the ignition circuit, thestarter solenoid and the accessories comprising contacts actuated by thefirst relay for supplying power to one group of accessories when thefirst relay alone is energized, other contacts actuated by the firstrelay and contacts actuated by the second relay for supplying power tothe starter solenoid and the ignition circuit when both relays areenergized, and means including the contacts actuated by the second relayand normally closed contacts of the first relay for supplying power tothe ignition circuit and both groups of accessories when the secondrelay only is energized.
 3. A circuit for an automotive vehicle foroperating an ignition circuit, a starter solenoid, and first and secondgroups of accessories, including a power supply and comprising first andsecond conductors, first and second relays connected with one side ofthe power supply and connected to the first and second conductorsrespectively, a key operated ignition switch connected for selectivelycompleting circuits with the conductors and the other side of the powersupply for energizing the first relay when in a first switch position,the second relay when in a second switch position, and both relays whenin a third switch position, the key forming a part of the switch andbeing in series with the power supply so that the circuits can beenergized only when the key is inserted in the key operated switch, anda switching circuit from the power supply to the ignition circuit, thestarter solenoid and the accessories comprising normally open contactsclosed by the first relay for supplying power to one group ofaccessories through normally closed contacts of the second relay whenthe first relay alone is energized, normally open contacts closed by thesecond relay and normally open contacts in series with the startersolenoid and the ignition circuit and closed by the first relay forsupplying power to the starter solenoid and the ignition circuit whenboth relays are energized, and means operative when the second relayonly is energized including the contacts closed by the second relay forsupplying power to the ignition circuit, and normally closed contacts ofthe first relay and further normally open contacts closed by the secondrelay for supplying power to both groups of accessories.